Part 1

Chapters 12 (AC Circuits), 13 (AC Measurements), and 14 (Resistive AC Circuits)

 

 

n  Each time an AC generator moves through one complete revolution, it is said to complete one

     _______________.  cycle

 

n  The rotating loop of wire in an AC generator is called the ____________________________.

     armature

 

n  The two halves of an AC cycle are referred to as __________________. alterations

 

n  One cycle per second is defined as a ____________________. hertz

 

n  The most basic and widely used of all the AC waveforms is the __________________________

     sinusoidal waveform

 

n  Each point on a sine wave has a pair of numbers associated with it.

 

    ð  The first value, the________________________________ is the angle to which the armature

          has returned.  degree of rotation

 

    ð  The second value, the  ___________________, is the maximum departure of the value of an

          AC current from the average value.  amplitude.

 

n  The _____________________________ of a sine wave is the absolute value of the point on the

     waveform with the greatest amplitude.  peak value

 

n  The ___________________________ value refers to the vertical distance between the two

     peaks. It can be found by adding the absolute value of each peak.  peak-to-peak

 

n  The _______________________ of alternating current is the amount that produces the same

     degree of heat in a given resistance as an equal amount of direct current.  effective value

 

n  The term rms value is often used. rms stands for ________________________ root mean square

 

n  The number of cycles that occur in a specific period of time is called the _____________________

     frequency

 

n  A current sine wave has a peak value of 10 amp. What is its effective value?

 

    I_rms = .707 I = 7.07 A

 

n  A voltage sine wave has an effective value of 707 volts. What is the peak value of the sine wave?

 

    V_rms = .707 V_peak   ð V_peak = 707/.707 = 1000 volts

 

n  What is the period of a sine wave that has a frequency of 100 hertz?

 

     t = 1/f = 1/100 = 0.01 seconds

 

n  Three nonsinusoidal waveforms were discussed in the text. List these waveforms below.

     If do not remember the names, can draw the waveform for partial credit

 

     ð  ______________________________  square

 

     ð  ______________________________  triangular

 

     ð  ______________________________  sawtooth

 

 

n  A very versatile piece of equipment for working on electronic equipment and circuits is the

     __________________________. It provides a visual display of what is occurring in the circuit,

     such a the frequency and duration of the signal and pulse relationships.  oscilloscope

 

n  CRT stands for _____________________________________. cathode ray tube

 

n  A __________________________________ measures frequency by comparing a known

     frequency against an input frequency.  frequency counter

 

n  The_____________________________ generates a range of frequencies over a specified

     spectrum. It allows the user to produce a graph of a circuit's frequency response.  Bode plotter

 

 

n  A basic AC circuit consists of the following 3 components

 

    ð  ____________________________________________________  source

 

    ð  ____________________________________________________  conductors

 

    ð  ____________________________________________________  resistive load

 

n  When an AC voltage is applied to the resistive load, the AC current's amplitude and direction vary

     in the same manner as those of the applied load. They are said to be ______________________

     in phase

 

n  The ______________________ of AC current or voltage produces the same results as the

     equivalent DC voltage or current.  effective value

 

n  Given an AC circuit that has an effective value of 120 volts applied across 2 resistors, R₁ and R₂ in

     series. R₁ = 25 W and R₂ = 35 W.

 

    ð  What is the equivalent resistance, R_E?

 

          R_E = 25 + 35 = 60 W

 

    ð  What is the total current?

 

         V = IR ð  I = V/R = 120/60 = 2 A

 

    ð  What is the voltage drop across R₂?

 

          V = IR = (2)(35) = 70 volts

 

n  Given an AC circuit that has an effective voltage of 120 volts applied across 2 parallel resistors,

     R₁ and R₂. R₁ = 470 ohms and R₂ = 1000 ohms.  What is the current flowing through R₂?

 

     In a parallel circuit,

 

     V_T = V_R1 = V_R2 = 120 volts

 

     I_R2 = = V_R2/R₂ = 120/1000 = 0.0120 A or 12 mA

 

n  AC current flowing in a conductor causes a magnetic field to expand and collapse as the current

    increases and decreases in value. This is the principle upon which the _____________________

    meter is based.  clamp on

 

n  A DC meter can be adapted to measure an AC signal by converting the AC voltage to a DC voltage

    using a _________________________. answer is not capacitor  rectifier

 

 

 

Part 2

Videos on Tesla and Edison

 

A description of either Edison or Tesla or neither is given in the first column. In the second column place a T (Tesla), an E (Edison), or an N (neither) depending on who the description refers to.

 

Description	Refers To
Born in Croatia	T
SI units for magnetic field named in his honor	T
Developed the stored program concept	N
Generally referred to as the father of AC	T
Had only 3 months of formal education	E
Invented the first successful electric light bulb	E
Developed the ENIAC	N
Invented the phonograph	E
Founded the first modern research laboratory	E
Established the first electrical power distribution company.	E
Worked on Wardenclyffe Tower project	T
Credited by Supreme Court as being the inventor of the radio	T